a. Field of Invention
The present invention relates to recloseable plastic bags, and more particularly to plastic bags having grip strips on their lips to facilitate the handling of the bags.
b. Description of the Prior Art
Plastic bags, and especially plastic bags with a zipper type recloseable closure have gained wide acceptance as a means of shipping and storing foodstuff as well as various other articles. Typically, these types of bags, at their opening end, are provided with two zipper strips. These strips may be formed integrally with the bag body or formed separately and attached to the film which provided the bag body. Each of these strips contains an interlocking profile and a lip disposed outwards of said profile. A problem that sometimes arises with these bags is that since they are typically made of a polyethylene they tend to feel slippery to the touch and as a result the lips are difficult to grip. The problem is somewhat exacerbated, when, as is often the case, the plastic bags are used for foodstuff and other materials used around a house and especially in the kitchen and the user's fingers are wet or oily. In such situations the bag lips become even more slippery and more difficult to handle.
U.S. Pat. No. 5,009,828 discloses a plastic bag having a plurality of parallel ridges on the lips to assist gripping the bag lips. However, these ridges have drawbacks since they extend parallel to the zipper profile and therefore tend to act as rails for a user's fingers rather than to provide a gripping surface. Further, such grip strips ridges are difficult to make, requiring a rather complicated die and head for the extrusion process.